Ross Ulbricht has been found guilty of operating the online drug marketplace known as the Silk Road. It took a jury less than four hours of deliberation to determine that Ulbricht, using the screen name Dread Pirate Roberts, facilitated millions of dollars worth of drug transactions on the anonymous market from February 2011 through October 2013. Ulbricht, 30, could spend the rest of his life in prison.

Ulbricht has been on trial in Manhattan federal court since Jan. 13, but it took the jury just three and a half hours Wednesday to find him guilty on seven counts, including two charges of distributing narcotics, engaging in a continuing criminal enterprise and four conspiracy counts. He pleaded not guilty to all charges.

The jury of six men and six women rejected defense attorney Joshua Dratel’s claim that Ulbricht, a computer programmer and physics scholar, founded the site but then walked away after a few months due to overwhelming stress.

Mandatory minimums in the case mean Ulbricht will spend 30 years in prison at the least -- and he could be sentenced to the rest of his natural life. His legal team is expected to file an appeal, in part because of frequent objections over what evidence was allowed into trial.

His sentence will be imposed May 15 by Judge Katherine Forrest of the U.S. District Court for the Southern District of New York. Forrest spent Wednesday morning instructing the jurors, advising them that their task was solely to determine Ulbricht’s guilt based on the evidence presented over the course of the trial.

“Your role is to pass upon and decide the facts in this case,” she said. “Common sense is your greatest asset as a juror.”

The prosecution portrayed Ulbricht as a controlling, manipulative 21st century drug lord who, instead of smuggling cocaine from Colombia, hid in plain sight in Internet cafes throughout the San Francisco Bay Area.

“We’re here to pull the curtain back on this dark and secret empire,” Assistant U.S. Attorney Timothy Howard pronounced during his opening statement. “He controlled his empire from behind a laptop computer.”

A series of government witnesses – including an undercover agent who worked directly under Ulbricht as a Silk Road administrator, an FBI computer expert and a former friend the defendant had confided in – took the stand to say Ulbricht was in fact the Dread Pirate Roberts.

The online entrepreneur was arrested on Oct. 1, 2013, in a San Francisco public library with his hands on the keyboard, while logged into the drug market as the Dread Pirate Roberts. The prosecution also cited a detailed diary Ulbricht kept of his crimes as well as myriad chat logs and personal correspondence to establish that he was heavily involved with the site and actively worked to shield his secret from those closest to him.

The defense launched a failed attempt to suggest that Ulbricht had been framed by Mark Karpeles, the founder and CEO of the bitcoin exchange Mt. Gox. Forrest quickly struck the line of questioning from the record, though, ruling that the defense violated the hearsay rule by asking the testifying witness for answers based in feeling, not fact.

“Criminals make mistakes all the time,” Howard said during the government’s closing argument Tuesday. “There are plenty of opportunities to make mistakes when you’re running a massive online criminal enterprise.”